Isolating 2 ckts from same pwr supply

[Elephant]

I want to use one 9vdc power supply to power two individual
circuits, but I want to isolate the two. In other words, the
two circuits have to act as though they are being powered from
seperate supplies, like two 9v batteries.

Can a diode arrangement be used for this?

 

[John Woodgate]

I read in sci.electronics.design that Elephant <elephant@the-zoo.com>
wrote (in <40779601.2775@the-zoo.com&gt about 'Isolating 2 ckts from same
pwr supply', on Fri, 9 Apr 2004:

I want to use one 9vdc power supply to power two individual
circuits, but I want to isolate the two. In other words, the
two circuits have to act as though they are being powered from
seperate supplies, like two 9v batteries.

Can a diode arrangement be used for this?

Probably not. It depends on the exact circuit arrangements, why you
want/need to keep them 'isolated', and even what you mean by that.

If their ground/earth/zero volts lines can't be connected together, the
problem is almost certainly insoluble.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Joerg]

With an isolating DC-DC converter this could probably be done.
Watch out for noise and other issues though.

Regards, Joerg.